1. Technical Field
This invention relates to hand-operable mechanical tools and, more particularly, to a manually operable taper key removal apparatus.
2. Prior Art
Tapered keys are commonly used with heavy machinery to lock a hub onto a shaft. Tapered keys accomplish this function when forcefully lodged into a notch, cut lengthwise on the shaft periphery, thereby expanding the shaft into a tight fit with the surrounding hub.
Specifically, tapered keys are employed to hold a sprocket, gear, flywheel, coupling or other such device onto a shaft, enabling such devices to turn or rotate with the shaft. Tapered keys are generally made of steel and are available in a variety of sizes, with a substantially rectangular shape that tapers on one side at a rate of approximately ⅛″ per foot. The larger end of a tapered key forms a rectangular block which can be pounded with a hammer to lodge the key into place. The block of a tapered key is not pounded flush against a hub, but extends out such that a space of approximately 1″ remains between the hub and the key block. On occasion, tapered keys will fracture under stress or otherwise require removal. Removal of a tapered key is difficult since they are lodged tightly in order to effectively secure one of the aforementioned devices to a shaft.
Removal of a tapered key is usually accomplished by pounding a wedge or other object between the hub and the block of the key in such a manner as to loosen the key from its position. If insufficient space exists between the hub and the key block or if the key is lodged too securely to effectively pry the key loose in this manner, an extension of some sort must be welded onto the end of the block such that the key can be pulled out by its extension. In either case, removal is difficult and time consuming. In addition, these methods are haphazard and can result in damage to the equipment and machinery involved or to the key itself.
Accordingly, a need remains for a taper key removal apparatus to over-come the above-noted shortcomings. The present invention satisfies such a need by providing a tool that facilitates the removal of such keys from gears, sprockets, and cams. Such an apparatus is easily struck by a hammer and may be used for removal and installation of taper keys. The present invention advantageously preserves the integrity of the taper keys by removing them undamaged, thereby permitting them to be reused, saving user's time and money.